All Free Biology MCQs with Answers

2121. The one that stores calcium is __________?

• A. Sarcolemma
• B. Sarcoplasm
• C. Sarcoplasmic reticulum
• D. Cytosol

Explanation: The sarcoplasmic reticulum is a specialised smooth endoplasmic reticulum that stores calcium ions and releases them to start muscle contraction. The likely mistake is sarcoplasm, which is the muscle-cell cytoplasm but is not the specialised calcium-storage network.

2122. Only myosine is present in_____________?

• A. A band
• B. 1 band
• C. H zone
• D. Sarcomere

Explanation: The H zone is the central part of the sarcomere containing thick myosin filaments without overlapping thin actin filaments, so only myosin is present there. Students may choose the A band because it contains myosin, but the A band also includes regions where actin overlaps myosin.

2123. There are about _________ muscles in human beings.

• A. 206
• B. 300
• C. 650
• D. 703

Explanation: The human body has about 600 to 650 skeletal muscles, so 650 is the accepted approximate figure. Students may choose 206 by confusing the number of bones in the adult skeleton with the number of muscles.

2124. Most abundant muscles in human beings?

• A. Skeletal Muscles
• B. Smooth Muscles
• C. Cardiac Muscles
• D. All of these

Explanation: Skeletal muscles are the most numerous and make up most of the muscle mass involved in voluntary movement and posture. Students may choose d because all three types are present in humans, but their abundance is not equal.

2125. The cardio respiratory capacity is related to____________?

• A. Strength
• B. Flexibility
• C. Normal physical endurance
• D. Agility

Explanation: Cardiorespiratory capacity measures how effectively the heart, lungs and blood supply oxygen during sustained activity, so it is most closely related to physical endurance. Strength concerns force production, whereas flexibility concerns range of motion; students may choose strength because both are components of physical fitness.

2126. S-band locomotion is characteristically seen in___________?

• A. Bony fish
• B. Cartilaginous fish.
• C. Fish like mammals.
• D. All fishes.Primary & Secondary Schooling (K-12)

Explanation: S-band or lateral undulatory locomotion is characteristically associated with cartilaginous fish, whose flexible bodies and fins produce side-to-side waves during swimming. Students may choose a because bony fish also swim by body and tail movements, but the question's traditional classification assigns this characteristic pattern to cartilaginous fish.

2127. Which of the following is the swiftest form of the locomotion?

• A. Plantigrade
• B. Digitigrade
• C. Unguligrade
• D. Hopping

Explanation: Unguligrade animals walk on the tips of their digits, often enclosed in hooves, which lengthens the effective limb and permits the greatest running speed. Students may choose b because digitigrade animals such as dogs and cats are also fast, but unguligrade locomotion is generally considered the swiftest of these foot postures.

2128. Which of the following animal uses Setae and Muscles for their Iocomotion?

• A. Cockroach
• B. Snail
• C. Earthworm
• D. Star fish

Explanation: An earthworm moves by alternating circular and longitudinal muscle contractions while its setae anchor parts of the body to the soil. The likely distractor is a snail, which mainly uses a muscular foot and mucus rather than setae for locomotion.

2129. Insertion of Biceps is on_________?

• A. Ulna
• B. Radius
• C. Olecronon process of ulna.
• D. Scapula

Explanation: The biceps brachii inserts mainly on the radial tuberosity and therefore attaches to the radius. The likely distractor is the ulna, because the biceps lies beside it in the forearm, but its insertion is on the radius.

2130. Which of the following muscle is an antagonistic member of Biceps brachii?

• A. Bracheoradialis
• B. Brachialis.
• C. Intercostals
• D. Triceps

Explanation: The triceps brachii opposes the biceps brachii: biceps flexes the elbow whereas triceps extends it. The likely distractor is brachialis, which also flexes the elbow and therefore acts more like a synergist than an antagonist.